Is it possible to change the color of the button of the referral notifications?

Summary:

Is it possible to change the color of the button and the text box of the notifications sent to candidates?

Content (required):

Hi,

in relation to the referral, when an employee refer a candidate, the candidate receives an email notification, that is the "Job Referral External Notification", editable in the "Recruiting Content Library" task. We would like to change the background color of the "View and apply" green button to another color, but we don't understand how to do it (first screenshot). Also, how can I increase the width of the light blue text box? (second screenshot).

Thank you